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2.
Int J Mol Sci ; 19(8)2018 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-30096912

RESUMO

Variations in substrate chemistry and the micro-structure were shown to have a significant effect on the biology of human mesenchymal stromal cells (hMSCs). This occurs when differences in the surface properties indirectly modulate pathways within numerous signaling networks that control cell fate. To understand how the surface features affect hMSC gene expression, we performed RNA-sequencing analysis of bone marrow-derived hMSCs cultured on tissue culture-treated polystyrene (TCP) and poly(l-lactide) (PLLA) based substrates of differing topography (Fl: flat and Fs: fibrous) and chemistry (Pr: pristine and Am: aminated). Whilst 80% of gene expression remained similar for cells cultured on test substrates, the analysis of differentially expressed genes (DEGs) revealed that surface topography significantly altered gene expression more than surface chemistry. The Fl and Fs topologies introduced opposite directional alternations in gene expression when compared to TCP control. In addition, the effect of chemical treatment interacted with that of topography in a synergistic manner with the Pr samples promoting more DEGs than Am samples in all gene ontology function groups. These findings not only highlight the significance of the culture surface on regulating the overall gene expression profile but also provide novel insights into cell-material interactions that could help further design the next-generation biomaterials to facilitate hMSC applications. At the same time, further studies are required to investigate whether or not the observations noted correlate with subsequent protein expression and functionality of cells.


Assuntos
Diferenciação Celular/genética , Proliferação de Células/genética , Células-Tronco Mesenquimais/citologia , Osteogênese/genética , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Células-Tronco Mesenquimais/metabolismo , Osteogênese/efeitos dos fármacos
3.
Int J Biol Macromol ; 277(Pt 1): 134112, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39048011

RESUMO

Designing stimuli-responsive drug delivery vehicles with higher drug loading capacity, sustained and targeted release of anti-cancer drugs and able to mitigate the shortcomings of traditional systems is need of hour. Herein, we designed stimuli-responsive, self-healable, and adhesive hydrogel through synergetic interaction between [Cho][Gly] (Choline-Glycine) and sodium alginate (SA). The hydrogel was formed as a result of non-covalent interaction between the components of the mixture forming the fibre kind morphology; confirmed through FTIR/computational analysis and SEM/AFM images. The hydrogel exhibited excellent mechanical strength, self-healing ability, adhesive character and most importantly; adjustable injectability. In vitro biocompatibility of the hydrogel was tested on HaCaT and MCF-7 cells, showing >92 % cell viability after 48 h. The hemolysis ratio (<4 %) of the hydrogel confirmed the blood compatibility of the hydrogel. When tested for drug-loading capacity, the hydrogel show 1500 times drug loading for the 5-fluorouracil (5-FU) against the SA based hydrogel. In vitro release data indicated that 5-FU have more preference towards the cancerous cell condition, i.e. acidic pH (>85 %), whereas the drug-loaded hydrogel successfully killed the MCF-7 and HeLa cell with a

Assuntos
Alginatos , Neoplasias da Mama , Liberação Controlada de Fármacos , Hidrogéis , Alginatos/química , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Hidrogéis/química , Células MCF-7 , Feminino , Portadores de Fármacos/química , Fluoruracila/farmacologia , Fluoruracila/química , Sobrevivência Celular/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Antineoplásicos/farmacologia , Antineoplásicos/química
4.
BMC Complement Altern Med ; 12: 30, 2012 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-22469333

RESUMO

BACKGROUND: Cephalotaxus spp. are known to possess various therapeutic potentials. Cephalotaxus griffithii, however, has not been evaluated for its biological potential. The reason may be the remoteness and inaccessibility of the habitat where it is distributed. The main aim of this study was to: (1) evaluate multiple biological potentials of stem bark of C. griffithii, and (2) identify solvent extract of stem bark of C. griffithii to find the one with the highest specific biological activity. METHODS: Dried powder of stem bark of C. griffithii was exhaustively extracted serially by soaking in petroleum ether, acetone and methanol to fractionate the chemical constituents into individual fractions or extracts. The extracts were tested for total phenolic and flavonoid content, antioxidant (DPPH radical scavenging, superoxide radical scavenging, and reducing power models), antibacterial (disc diffusion assay on six bacterial strains), cytotoxic (MTT assay on HeLa cells), and apoptotic activity (fluorescence microscopy, DNA fragmentation assay, and flow cytometry on HeLa cells). RESULTS: Among the three extracts of stem bark of C. griffithii, the acetone extract contained the highest amount of total phenolics and flavonoids and showed maximum antioxidant, antibacterial, cytotoxic (IC50 of 35.5 ± 0.6 µg/ml; P < 0.05), and apoptotic (46.3 ± 3.6% sub-G0/G1 population; P < 0.05) activity, followed by the methanol and petroleum ether extracts. However, there was no significant difference observed in IC50 values (DPPH scavenging assay) of the acetone and methanol extracts and the positive control (ascorbic acid). In contrast, superoxide radical scavenging assay-based antioxidant activity (IC50) of the acetone and methanol extracts was significantly lower than the positive control (P < 0.05). Correlation analysis suggested that phenolic and flavonoid content present in stem bark of C. griffithii extracts was responsible for the high antioxidant, cytotoxic, and apoptotic activity (P < 0.05). CONCLUSIONS: Stem bark of C. griffithii has multiple biological effects. These results call for further chemical characterization of acetone extract of stem bark of C. griffithii for specific bioactivity.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/uso terapêutico , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Cephalotaxus/química , Fitoterapia , Extratos Vegetais , Antineoplásicos Fitogênicos/farmacologia , Flavonoides/análise , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Células HeLa , Humanos , Fenóis/análise , Fenóis/farmacologia , Fenóis/uso terapêutico , Casca de Planta , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Caules de Planta
5.
Tissue Eng Regen Med ; 19(4): 659-673, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35384633

RESUMO

The unprecedented COVID-19 pandemic situation forced the scientific community to explore all the possibilities from various fields, and so far we have seen a lot of surprises, eureka moments and disappointments. One of the approaches from the cellular therapists was exploiting the immunomodulatory and regenerative potential of mesenchymal stromal cells (MSCs), more so of MSC-derived extracellular vesicles (EVs)-particularly exosomes, in order to alleviate the cytokine storm and regenerate the damaged lung tissues. Unlike MSCs, the EVs are easier to store, deliver, and are previously shown to be as effective as MSCs, yet less immunogenic. These features attracted the attention of many and thus led to a tremendous increase in publications, clinical trials and patent applications. This review presents the current landscape of the field and highlights some interesting findings on MSC-derived EVs in the context of COVID-19, including in silico, in vitro, in vivo and case reports. The data strongly suggests the potential of MSC-derived EVs as a therapeutic regime for the management of acute lung injury and associated complications in COVID-19 and beyond.


Assuntos
COVID-19 , Vesículas Extracelulares , Lesão Pulmonar , Células-Tronco Mesenquimais , COVID-19/terapia , Humanos , Pandemias
6.
ACS Omega ; 7(34): 29634-29646, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36061739

RESUMO

Owing to the shortage of donor corneas and issues associated with conventional corneal transplantation, corneal tissue engineering has emerged as a promising therapeutic alternative. Biocompatibility and other attractive features make silk fibroin a biomaterial of choice for corneal tissue engineering applications. The current study presents three modes of silk fibroin film fabrication by solvent casting with popular solvents, viz. aqueous (aq), formic acid (FA), and hexafluoroisopropanol (HFIP), followed by three standard modes of postfabrication annealing with water vapor, methanol vapor, and steam, and systematic characterization studies including corneal cell culture in vitro. The results indicated that silk fibroin films made from aq, FA, and HFIP solvents had surface roughness (Rq) of 1.39, 0.32, and 0.13, contact angles of 73°, 85°, and 89°, water uptake% of 58, 29, and 27%, swelling ratios of 1.58, 1.3, and 1.28, and water vapor transmission% of 39, 26, and 22%, respectively. The degradation rate was in the order of aq > HF > FA, whereas the tensile strength was in the order of aq < HF < FA. Further, the results of the annealing process indicated notable changes in morpho-topographical, physical, degradation, and tensile properties. However, the films showed no detectable changes in chemical composition and remained optically clear with >90% transmission in the visible range, irrespective of fabrication and postfabrication processing conditions. The films were noncytotoxic against L929 cells and were cytocompatible with rabbit cornea-derived SIRC cells in vitro. The study demonstrated the potential of fine-tuning various properties of silk fibroin films by varying the fabrication and postfabrication processing conditions.

7.
Int J Biol Macromol ; 207: 278-288, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35257733

RESUMO

Three dimensional (3D) bioprinting technology has been making a progressive advancement in the field of tissue engineering to produce tissue constructs that mimic the shape, framework, and microenvironment of an organ. The technology has not only paved the way to organ development but has been widely studied for its application in drug and cosmetic testing using 3D bioprinted constructs. However, not much has been explored on the utilization of bioprinting technology for the development of tumor models to test anti-cancer drug efficacy. The conventional methodology involves a two dimensional (2D) monolayer model to test cellular drug response which has multiple limitations owing to its inability to mimic the natural tissue environment. The choice of bioink for 3D bioprinting is critical as cell morphology and proliferation depend greatly on the property of bioink. In this study, we developed a multicomponent bioink composed of alginate, diethylaminoethyl cellulose, gelatin, and collagen peptide to generate a 3D bioprinted construct. The bioink has been characterised and validated for its printability, shape fidelity and biocompatibility to be used for generating tumor models. Further, a bioprinted tumor model was developed using lung cancer cell line and the efficacy of 3D printed construct for drug screening application was established.


Assuntos
Bioimpressão , Alginatos/química , Bioimpressão/métodos , Celulose , Colágeno , Avaliação Pré-Clínica de Medicamentos , Gelatina , Peptídeos/farmacologia , Impressão Tridimensional , Engenharia Tecidual/métodos , Alicerces Teciduais/química
8.
Int J Biol Macromol ; 189: 398-409, 2021 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-34419550

RESUMO

INTRODUCTION: Biofabrication of skin tissue equivalents using 3D bioprinting technology has gained much attention in recent times due to the simplicity, the versatility of the technology and its ability in bioengineering biomimetic tissue histology. The key component being the bioink, several groups are actively working on the development of various bioink formulations for optimal skin tissue construction. METHODS: Here, we present alginate (ALG), gelatin (GEL) and diethylaminoethyl cellulose (DCEL) based bioink formulation and its application in bioprinting and biofabrication of skin tissue equivalents. Briefly, DEAE cellulose powder was dispersed in alginate solution with constant stirring at 60 °C to obtain a uniform distribution of cellulose fibers; this was then mixed with GEL solution to prepare the bioink. The formulation was systematically characterized for its morphological, physical, chemical, rheological, biodegradation and biocompatibility properties. The printability, shape fidelity and cell-laden printing were assessed using the CellInk bioprinter. RESULTS: The bioink proved to be a good printable, non-cytotoxic and stable hydrogel formulation. The primary human fibroblast and keratinocyte-loaded 3D bioprinted constructs showed excellent cell viability, collagen synthesis, skin-specific marker and biomimetic tissue histology. CONCLUSION: The results demonstrated the successful formulation of ALG-GEL-DCEL bioink and its application in the development of human skin tissue equivalents with distinct epidermal-dermal histological features.


Assuntos
Alginatos/farmacologia , DEAE-Celulose/química , Gelatina/farmacologia , Tinta , Microtecnologia , Pele/efeitos dos fármacos , Engenharia Tecidual , Alicerces Teciduais/química , Adulto , Animais , Materiais Biocompatíveis/química , Biomarcadores/metabolismo , Bioimpressão , Linhagem Celular , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Camundongos , Impressão Tridimensional , Reologia , Pele Artificial , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Nanomedicine ; 6(1): 153-60, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19616123

RESUMO

We report a nanoformulation of curcumin with a tripolymeric composite for delivery to cancer cells. The composite nanoparticles (NPs) were prepared by using three biocompatible polymers-alginate (ALG), chitosan (CS), and pluronic-by ionotropic pre-gelation followed by polycationic cross-linking. Pluronic F127 was used to enhance the solubility of curcumin in the ALG-CS NPs. Atomic force and scanning electron microscopic analysis showed that the particles were nearly spherical in shape with an average size of 100 +/- 20 nm. Fourier transform-infrared analysis revealed potential interactions among the constituents in the composite NPs. Encapsulation efficiency (%) of curcumin in composite NPs showed considerable increase over ALG-CS NPs without pluronic. The in vitro drug release profile along with release kinetics and mechanism from the composite NPs were studied under simulated physiological conditions for different incubation periods. A cytotoxicity assay showed that composite NPs at a concentration of 500 microg/mL were nontoxic to HeLa cells. Cellular internalization of curcumin-loaded composite NPs was confirmed from green fluorescence inside the HeLa cells. The half-maximal inhibitory concentrations for free curcumin and encapsulated curcumin were found to be 13.28 and 14.34 muM, respectively. FROM THE CLINICAL EDITOR: A nanoformulation of curcumin with a tri-component polymeric composite for delivery to cancer cells is reported in this paper. Cellular internalization of curcumin loaded composite nanoparticles was confirmed from green fluorescence inside the HeLa cells.


Assuntos
Alginatos/química , Quitosana/química , Curcumina/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Neoplasias/metabolismo , Poloxâmero/química , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ácido Glucurônico/química , Células HeLa , Ácidos Hexurônicos/química , Humanos , Cinética , Microscopia de Fluorescência , Nanocompostos/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Bioengineering (Basel) ; 7(3)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32916945

RESUMO

Layer-by-layer additive manufacturing process has evolved into three-dimensional (3D) "bio-printing" as a means of constructing cell-laden functional tissue equivalents. The process typically involves the mixing of cells of interest with an appropriate hydrogel, termed as "bioink", followed by printing and tissue maturation. An ideal bioink should have adequate mechanical, rheological, and biological features of the target tissues. However, native extracellular matrix (ECM) is made of an intricate milieu of soluble and non-soluble extracellular factors, and mimicking such a composition is challenging. To this end, here we report the formulation of a multi-component bioink composed of gelatin and alginate -based scaffolding material, as well as a platelet-rich plasma (PRP) suspension, which mimics the insoluble and soluble factors of native ECM respectively. Briefly, sodium alginate was subjected to controlled oxidation to yield alginate dialdehyde (ADA), and was mixed with gelatin and PRP in various volume ratios in the presence of borax. The formulation was systematically characterized for its gelation time, swelling, and water uptake, as well as its morphological, chemical, and rheological properties; furthermore, blood- and cytocompatibility were assessed as per ISO 10993 (International Organization for Standardization). Printability, shape fidelity, and cell-laden printing was evaluated using the RegenHU 3D Discovery bioprinter. The results indicated the successful development of ADA-gelatin-PRP based bioink for 3D bioprinting and biofabrication applications.

11.
Biomater Sci ; 8(2): 746, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31829313

RESUMO

Correction for 'Bioengineering a pre-vascularized pouch for subsequent islet transplantation using VEGF-loaded polylactide capsules' by Naresh Kasoju et al., Biomater. Sci., 2020, DOI: 10.1039/c9bm01280j.

12.
Biomater Sci ; 8(2): 631-647, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31729495

RESUMO

The effectiveness of cell transplantation can be improved by optimization of the transplantation site. For some types of cells that form highly oxygen-demanding tissue, e.g., pancreatic islets, a successful engraftment depends on immediate and sufficient blood supply. This critical point can be avoided when cells are transplanted into a bioengineered pre-vascularized cavity which can be formed using a polymer scaffold. In our study, we tested surface-modified poly(lactide-co-caprolactone) (PLCL) capsular scaffolds containing the pro-angiogenic factor VEGF. After each modification step (i.e., amination and heparinization), the surface properties and morphology of scaffolds were characterized by ATR-FTIR and XPS spectroscopy, and by SEM and AFM. All modifications preserved the gross capsule morphology and maintained the open pore structure. Optimized aminolysis conditions decreased the Mw of PLCL only up to 10% while generating a sufficient number of NH2 groups required for the covalent immobilization of heparin. The heparin layer served as a VEGF reservoir with an in vitro VEGF release for at least four weeks. In vivo studies revealed that to obtain highly vascularized PLCL capsules (a) the optimal VEGF dose for the capsule was 50 µg and (b) the implantation time was four weeks when implanted into the greater omentum of Lewis rats; dense fibrous tissue accompanied by vessels completely infiltrated the scaffold and created sparse granulation tissue within the internal cavity of the capsule. The prepared pre-vascularized pouch enabled the islet graft survival and functioning for at least 50 days after islet transplantation. The proposed construct can be used to create a reliable pre-vascularized pouch for cell transplantation.


Assuntos
Bioengenharia , Transplante das Ilhotas Pancreáticas , Neovascularização Fisiológica , Poliésteres/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Glicemia/análise , Cápsulas/química , Cápsulas/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Injeções Intraperitoneais , Masculino , Estrutura Molecular , Tamanho da Partícula , Poliésteres/química , Ratos , Ratos Endogâmicos Lew , Estreptozocina/administração & dosagem , Fatores de Crescimento do Endotélio Vascular/química
13.
J Funct Biomater ; 10(3)2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31324062

RESUMO

Tissue engineering aims to develop artificial human tissues by culturing cells on a scaffold in the presence of biochemical cues. Properties of scaffold such as architecture and composition highly influence the overall cell response. Electrospinning has emerged as one of the most affordable, versatile, and successful approaches to develop nonwoven nano/microscale fibrous scaffolds whose structural features resemble that of the native extracellular matrix. However, dense packing of the fibers leads to small-sized pores which obstruct cell infiltration and therefore is a major limitation for their use in tissue engineering applications. To this end, a variety of approaches have been investigated to enhance the pore properties of the electrospun scaffolds. In this review, we collect state-of-the-art modification methods and summarize them into six classes as follows: approaches focused on optimization of packing density by (a) conventional setup, (b) sequential or co-electrospinning setups, (c) involving sacrificial elements, (d) using special collectors, (e) post-production processing, and (f) other specialized methods. Overall, this review covers historical as well as latest methodologies in the field and therefore acts as a quick reference for those interested in electrospinning matrices for tissue engineering and beyond.

14.
J Biomed Mater Res A ; 107(1): 122-133, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30256517

RESUMO

Mesenchymal stem cells (MSCs) are potential therapeutic candidates, owing to their ability to differentiate into several cell types. However, the gap between availability and demand of MSCs requires alternative expansion methods from 2D culture flasks. Microcarriers are a promising approach for MSC expansion due to their high surface area-to-volume ratio. However, current commercial microcarriers do not provide the highest cell yield due to low cell attachment efficiencies and difficulty in cell detachment. This study developed a hydrogel-based microcarrier from genipin cross-linked alginate-chitosan beads. Alginate beads were produced by electrospraying before being coated with chitosan and cross-linked in genipin. The degree of cross-linking was determined through fluorescence reading of the genipin-chitosan conjugates. MSCs cultured on these microcarriers had a 26% higher cell attachment and twice the proliferation rate compared to the commercial microcarrier Cytodex 1. Cells easily detached from the hydrogel beads and did not require extended incubation periods or intense agitation during cell harvest. There was no significant difference in gene expression between the two microcarriers for the positive MSC surface markers CD-90, CD-105, and CD-73 as well as showing either low or no signal for negative MSC surface markers CD-45 and CD-34. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 122-133, 2019.


Assuntos
Alginatos , Técnicas de Cultura de Células , Quitosana , Iridoides , Células-Tronco Mesenquimais/metabolismo , Microesferas , Alginatos/química , Alginatos/farmacologia , Linhagem Celular Transformada , Quitosana/química , Quitosana/farmacologia , Humanos , Iridoides/química , Iridoides/farmacologia , Células-Tronco Mesenquimais/citologia
15.
Biomed Mater ; 14(3): 035012, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30849767

RESUMO

Culturing human Mesenchymal stromal cells (hMSCs) in vitro in hypoxic conditions resulted in reduced senescence, enhanced pluripotency and altered proliferation rate. It has been known that in vitro hypoxia affects expression of cell surface proteins. However, the impact of culture surfaces on the hypoxia-regulated genes (HRG) have not yet been reported. This study utilized Next-Generation sequencing to analyse the changes in the gene expression levels of HRG for hMSCs cultured on different culture surfaces. The samples, which were cultured on four different synthesized surfaces (treatments) and tissue culture plate (control), resulted in a difference in growth rate. The sequencing results revealed that the transcription of a number of key genes involved in regulating hypoxic functions were significantly altered, including HIF2A, a marker for potency, differentiation, and various cellular functions. Significant alternations in the expression levels of previously reported oxygen-sensitive surface proteins were detected in this study, some of which closely correlate with the expression levels of HIF2A. Our analysis of the hMSCs transcriptome and HRG mapped out a list of genes encoding surface proteins which may directly regulate or be regulated by HIF2A. The findings from this study showed that culture surfaces have an impact on regulating the expression profile of HRG. Therefore, novel culture surfaces may be designed to selectively activate HIF2A and other HRG and pathways under in vitro normoxia. The understanding of the crosstalk between the regulating genes of hypoxia and culture surfaces may be utilized to strengthen desired hypoxic functions.


Assuntos
Regulação da Expressão Gênica , Células-Tronco Mesenquimais/citologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Células da Medula Óssea/metabolismo , Diferenciação Celular , Hipóxia Celular , Proliferação de Células , Células Cultivadas , Análise por Conglomerados , Perfilação da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Oxigênio/metabolismo , Propriedades de Superfície
16.
Int J Stem Cells ; 12(1): 84-94, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30836724

RESUMO

BACKGROUND AND OBJECTIVES: The International Society for Cellular Therapy (ISCT) proposed a set of minimal markers for identifying human mesenchymal stromal cells (hMSCs) in 2007. Since then, with the growing interest of better characterising hMSCs, various additional surface markers have been proposed. However, the impact of how culture conditions, in particular, the culture surface, vary the expression of hMSC markers was overlooked. METHODS AND RESULTS: In this study, we utilized the RNA sequencing data on hMSCs cultured on different surfaces to investigate the variation of the proposed hMSC biomarkers. One of the three ISCT proposed positive biomarker, CD90 was found to be significantly down regulated on hMSCs culture on fibrous surfaces when compared to flat surfaces. The detected gene expression values for 177 hMSCs biomarkers compiled from the literature are reported here. Correlation and cluster analysis revealed the existence of different biomarker communities that displayed a similar expression profile. We found a list of hMSCs biomarkers which are the least sensitive to a change in surface properties and another list of biomarkers which are found to have high sensitivity to a change in surface properties. CONCLUSIONS: This study demonstrated that substrate properties have paramount effect on altering the expressions of hMSCs biomarkers and the proposed list of substrate-stable and substrate-sensitive biomarkers would better assist in the population characterisation. However, proteomic level analysis would be essential to confirm the observations noted.

17.
Biomacromolecules ; 9(10): 2905-12, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18785706

RESUMO

In milk caseins exists a natural nanostructure, which can be exploited as a carrier of hydrophobic drugs. Here we investigated the complex formation of curcumin with bovine casein micelles (CMs) and its use as a vehicle for drug delivery to cancer cells. DLS studies of the CM suspension that was stable in buffer solution (pH 7.4) showed an average size distribution of <200 nm. SEM and AFM studies showed that the particles were roughly spherical in shape. Steady-state fluorescence spectroscopy of the CM-curcumin complex formation revealed that curcumin molecules formed complexes with CMs (CM-curcumin complex) through hydrophobic interactions. The binding constant for the CM-curcumin interaction was calculated to be 1.48 x 10(4) M(-1), as determined by the curcumin fluorescence. Fluorescence quenching showed that curcumin molecules quench the intrinsic fluorescence of caseins upon binding. We evaluated the utility of CMs as carriers of curcumin by using in vitro cultured HeLa cells. Cytotoxicity studies of HeLa cells revealed that the IC50 of free curcumin and the CM-curcumin complex was 14.85 and 12.69 microM, respectively.


Assuntos
Caseínas/química , Curcumina/química , Portadores de Fármacos , Micelas , Microscopia de Fluorescência/métodos , Neoplasias/tratamento farmacológico , Sobrevivência Celular , Células HeLa , Humanos , Microscopia de Força Atômica , Modelos Químicos , Conformação Molecular , Nanopartículas/química , Ligação Proteica , Fatores de Tempo
18.
Nanomaterials (Basel) ; 8(10)2018 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-30347891

RESUMO

Electrospinning uses an electric field to produce fine fibers of nano and micron scale diameters from polymer solutions. Despite innovation in jet initiation, jet path control and fiber collection, it is common to only fabricate planar and tubular-shaped electrospun products. For applications that encapsulate cells and tissues inside a porous container, it is useful to develop biocompatible hollow core-containing devices. To this end, by introducing a 3D-printed framework containing a sodium chloride pellet (sacrificial core) as the collector and through post-electrospinning dissolution of the sacrificial core, we demonstrate that hollow core containing polyamide 66 (nylon 66) devices can be easily fabricated for use as cell encapsulation systems. ATR-FTIR and TG/DTA studies were used to verify that the bulk properties of the electrospun device were not altered by contact with the salt pellet during fiber collection. Protein diffusion investigations demonstrated that the capsule allowed free diffusion of model biomolecules (insulin, albumin and Ig G). Cell encapsulation studies with model cell types (fibroblasts and lymphocytes) revealed that the capsule supports the viability of encapsulated cells inside the capsule whilst compartmentalizing immune cells outside of the capsule. Taken together, the use of a salt pellet as a sacrificial core within a 3D printed framework to support fiber collection, as well as the ability to easily remove this core using aqueous dissolution, results in a biocompatible device that can be tailored for use in cell and tissue encapsulation applications.

19.
Biotechnol Adv ; 35(4): 407-418, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28450077

RESUMO

The plastic-adherent, fibroblast-like, clonogenic cells found in the human body now defined as multipotent "Mesenchymal Stromal Cells" (MSCs) hold immense potential for cell-based therapies. Recently, research and basic knowledge of these cells has fast-tracked, both from fundamental and translational perspectives. There have been important discoveries with respect to the available variety of tissue sources, the development of protocols for their easy isolation and in vitro expansion and for directed differentiation into various cell types. In addition, there has been discovery of novel abilities such as immune-modulation and further development of the use of biomaterials to aid isolation, expansion and differentiation together with improved delivery to the selected optimal tissue site. However, the molecular fingerprint of MSCs in these contexts remains imprecise and inadequate. Consequently, without this crucial knowledge it is difficult to achieve progress to determine with precision their practical developmental potentials. Detailed investigations on the global gene expression, or transcriptome, of MSCs could offer essential clues in this regard. In this article, we address the challenges associated with MSC transcriptome studies, the paradoxes observed in published experimental results and the need for careful transcriptomic analysis. We describe the exemplary applications with various transcriptome platforms that are used to address the variation in biomarkers and the identification of differentiation processes. The evolution and the potentials for adapting next-generation sequencing (NGS) technology in transcriptome analysis are discussed. Lastly, based on review of the existing understanding and published studies, we propose how NGS may be applied to promote further understanding of the biology of MSCs and their use in allied fields such as regenerative medicine.


Assuntos
Perfilação da Expressão Gênica , Células-Tronco Mesenquimais , Transcriptoma , Diferenciação Celular , Perfilação da Expressão Gênica/métodos , Perfilação da Expressão Gênica/tendências , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Medicina Regenerativa
20.
Biomater Sci ; 4(3): 460-73, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26730413

RESUMO

Tissue engineering benefits from novel materials with precisely tunable physical, chemical and mechanical properties over a broad range. Here we report a practical approach to prepare Bombyx mori silk fibroin hydrogels using the principle of non-solvent induced phase separation (NIPS). A combination of reconstituted silk fibroin (RSF) and methanol (non-solvent), with a final concentration of 2.5% w/v and 12.5% v/v respectively, maintained at 22 °C temperature turned into a hydrogel within 10 hours. Freeze-drying of this gel gave a foam with a porosity of 88%, a water uptake capacity of 89% and a swelling index of 8.6. The gelation kinetics and the loss tangent of the gels were investigated by rheometry. The changes in the morphology of the porous foams were visualized by SEM. The changes in RSF chemical composition and the relative fraction of its secondary structural elements were analyzed by ATR-FTIR along with Fourier self-deconvolution. And, the changes in the glass transition temperature, specific heat capacity and the relative fraction of crystallinity of RSF were determined by TM-DSC. Data suggested that RSF-water-methanol behaved as a polymer-solvent-non-solvent ternary phase system, wherein the demixing of the water-methanol phases altered the thermodynamic equilibrium of RSF-water phases and resulted in the desolvation and eventual separation of the RSF phase. Systematic analysis revealed that both gelation time and the properties of hydrogels and porous foams could be controlled by the ratios of RSF and non-solvent concentration as well as by the type of non-solvent and incubation temperature. Due to the unique properties we envisage that the herein prepared NIPS induced RSF hydrogels and porous foams can possibly be used for the encapsulation of cells and/or for the controlled release of both hydrophilic and hydrophobic drugs.


Assuntos
Materiais Biocompatíveis/química , Bombyx/química , Fibroínas/química , Hidrogéis/química , Solventes/química , Animais , Interações Hidrofóbicas e Hidrofílicas , Porosidade , Temperatura , Engenharia Tecidual
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